Frankly, I think (and I don’t know one single Jihadist) that it’s a lot simpler. They do this, not because they actually believe they are going to win anytime soon, but they do this where they can in order to terrorize “westerners” or anyone intermingling with your trademark “immoral or amoral, money grubbing, powerhungry evil westerner” type. Hence Bali and not Cancun. It’s a lot simpler to do this where you live rather than to travel across the world. And making us types shiver in our boots, or quit traveling to tourist destinations in the line of fire is satisfying.